:Command list

:directive,number of
parameters,description,optional parameters,recognized option words

:title
1
defines the title of the exercise

:language
1
defines the language of the exercise, such as en or fr

:author
1
defines the author of the exercise. Write it in the form firstname, lastname (in case of multiple authors, use a semicolon between them).

:email
1
defines the author's email (in case of multiple authors, use a comma between the addresses).

:format
1
format of the statement

help=format
:css
1
defines css style

:keywords
1
Exercise keywords

:credits
1
allows to insert credits at the end of the exercise (variables are evaluated).

:description
1
description of the exercise for the students

:observation
1
description of the exercise for the teacher

:precision
1
precision in comparing user's reply with the solution. Give a positive integer n here: the comparison will be done to the precision of 1/n.

:range
1
variable range when evaluating a function supplied by the user. Should be given in the form n1..n2, where n1 is the start point, n2 is the end point.

:computeanswer
1
The instruction \computeanswer{ no } specifies that the user should complete calculations by himself and enter the final value. On the other hand, if we specify \computeanswer{ yes }, the user may enter a formula like 5*5,  letting the computer make the calculations.

:statement
1
the parameter is the statement of the exercise. Can be used only one time in the exercise.

:answer
2-5
defines a freestyle answer. The first parameter is the prompt of the answer, and the second is the good answer.  Such an answer can be tested according to many different types: number, function, text, etc.
type option weight
reorder shuffle nonstop
help=reply

:choice
3-5
defines a multiple choice. The first parameter is the prompt of the choice, the second the good choice(s), and the third the other choice(s). The last two parameters may (should) be a comma-separated list. Multiple good choices are allowed. If a choice appears in both good and bad choice lists, it will be taken as good.
option weight
shuffle noidontknow

:condition
2-4
defines a special condition for the evaluation of freestyle answers.
option weight
hide
help=reply

:solution
1
gives the solution of the exercise with explanation. The OEF manager may decide on whether to show this explained solution to the user, according to the user setup of the difficulty level. Can be used only one time in the exercise.

:hint
1
gives a hint of the exercise. The OEF manager may decide on whether to show the hint, according to the user setup of the difficulty level. Can be used only one time in the exercise.

:help
1
gives a help to the exercise. This help will always be accessible to the user, in a popup window. Can be used only one time in the exercise.

:feedback
2
gives a feedback warning to the user when the answer meeds a specified condition. Usually to warn of a typical error.

help=feedback

:steps
1
defines the questions of each step of the exercise ; must be before the instruction statement (see the variable \step). Can be used only one time in the exercise.

:nextstep
1
defines the questions of each step of the exercise in a dynamic way ; must be before the instruction statement (see the variable \step). Can be used only one time in the exercise.

:conditions
1
defines the numbers of the conditions useful for the exercise.

:latex
1
allows to write a latex version of the exercise using the variables defined in the exercise and downloadable in the printable version of the exercise (accessible only by developers or teachers of a class). It is advisable to put the statement in a predefined environment latex \begin{statement} \end{statement} and the solution in the environment \begin{solution} ... \end{solution}.
